Intermediates for the production of vitamin b6 and processes of preparing the same



Patented Apr. 3, 1945 INTERMEDIATES FOR THE PRODUCTION OF VITAMIN Bo AND PROCESSES OF PBEPAR- ING THE SAME Eric T. Stiller, New York, N.- Y., assignor to Merck N: J., a corporation of New & 00., Inc., Rahway, Jersey No Drawing.

Application November 15, 1940, Serial No. 365,758

v 7 Claims. (01. 260-297) This invention relates to intermediates for the production of vitamin Be, and to processes of preparing the same.

I have discovered, that compounds of the formula:

wherein R is selected from the group consisting of methyl and alkoxymethyl, and R1 is selected from the group consisting of acylamino, acylaminomethyl and aminomethyl, are valuable intermediates for the production of vitamin B6.

The novel compounds of the present invention may be prepared, for example, by reacting 3- acetylamino-acetyl-acetone with cyanoacetamide in the presence of an organic'solvent, and a basic catalyst selected from the group consisting of an aliphatic amine and a saturated heterocyclic amine to form 3-cyano-4,6-dimethyl-5- acetylamino-pyridone-2.

Upon reacting 3-acetylamino- 1 -ethoxypentane-, 2,4-dione and cyanoacetamide in the presence of an organic solvent, and the above basic catalyst, there is obtained 3-cyano-4-ethoxymethyl-5- acetylamino-6 methyl pyridone-2.

Upon reacting 3-benzoylaminomethylrpentane- 2,4-dione with cyanoacetamide in the presence of an organic solvent, and the above basic catalyst; there is obtained 3-cyano-4,6-difnethy1-5-benzoylaminomethyl:pyridone-2.

Upon reacting lqethoxy-3-benzoylaminomethyl-pentane-2,4-dione andcyanoacetamide in the presence of an organic solvent, and the above basic catalyst, there is obtained 3-cyano-4- ethoxymethyl benzoylaminomethyl-fi-methylpyridone-2.

Emmple I 0.5 gm. of 3-acetylamino-acetyl-acetone are mixed with 0.27 gm. of cyanoacetamide, and disstanding for some hours, the crystalline material solved in 18 cc. of alcohol. Three drops 01} piperidin'e are added, and the solution refluxed for minutes, during which time crystalline material Example II 2 gms. of 3-acetylamino-1-ethoxypentane-2,4- dione and 0.85 gm. of cyanoacetamide are dissolved in 25 cc. of alcohol, and six drops of piperidine are added. The mixture is refluxed for two hours and then cooled to 0 C. After is filtered oil, and recrystallized from alcohol.

3 cyano 4 ethoxymethyl 5 acetylamino 6- methyl-pyridone-Z is obtained 'as clusters of colorless flne needles, M. P. 262 -3 (decomposition). Example!!! 0.55 gm. of 3-benzoylaminomethyl-pentane- 2,4-dione in 10 cc. of dioxane are mixed with 0.2- gm. of cyanoacetamide, and ,two drops 01' piperidine are added. The mixture is refluxed for three hours. On cooling, and the addition of a little water, crystallization takes place. 3 cyano-4,6-di'methyl 5 benzoylaminomethylpyridone-2 is obtained in the form of colorless prisms, M. P. 316 C. (decomposition).

Example IV 1.65 .gms. of 1-ethoxy-3-benzoylaminomethyl If desired, the end products of Examples 1 and 2 may be hydrolyzed to the 5-amino compoundby treatment with hydrochloric acid, and the end products of Examples 3 and 4 may be hydrolyzed to the 5-aminomethyl compound byv treatment with hydrochloric acid.

'Other alkoxymethyl substituents in the (4 position may be obtained, for example, by con- (lensing 1-methoxy-3-acetyl-amino-pentane-2,4- dione, or 1-inethoxy-3-benzoylaminomethylpentane- 2,4-dione with cyanoacetamide in the presence of an organic solvent and the basic catalyst.

Other pyridones, having an acylamino or acylaminomethyl group as a substituent in the (5) position, may be obtained by condensing other appropriate l-alko'xy-3-acylamino-pentane-2,4-

dione or l-alkoxy-S-acylaminomethyl-pentane- 2,4-dione with cyanoacetamide in the presence of an organic solvent and the basic catalyst. Coming application Serial No. 309,574, filed December 16, 1939, which is now Patent 2,306,765 issued December 29, 1942.

Modifications may be made in carrying out the present invention without departing from the spirit and scope thereof, and I am to be limited only by the appended claims.

I claim:

1. 3-cyano-4,6 -dimethyl-5-acetylamino pyridcne-2.

.2. In the process of preparing a vitamin B5 intermediate, the step which comprises reacting 3-acetylamino-acety1acetone and cyanoacetamide in the presence of an organic solvent, and a basic catalyst selected from the group consisting of an aliphatic amine and a saturated heterocyclic amine.

3. In the process of preparing a vitamin B5 intermediate, the stepwhich comprises reacting 3-acetylamino-l-ethoxypentane 2,4 dione and cyanoacetamide in the presence of an organic solvent, and a basic catalyst selected from the group consisting of an aliphatic amine and a saturated heterocyclic amine.

4. In the process of preparing a vitamin B6 intermediate, the step comprising reacting a compound of the formula pounds of this type are disclosed in my copendin which R1 is selected from the group consistiris of hydrogen and alkoxy radicals. and R2 is acylamino; and cyanoacetamide in the presence of an organic solvent, and a basic catalyst selected from the group consisting of-an aliphatic amine and a saturated heterocyclic amine.

5. In the process of preparing a vitamin B3 intermediate, the step which comprises reacting l-alkoxy-S-acylamino-pentane 2:4 dione and cyanoacetamide in the presence of an organic solvent and a basic catalyst selected from the group consisting of an aliphatic amine and a J: saturated heterocyclic amine.

6. In the process of preparing a vitamin B0 intermediate, the step which comprises reacting a 3-acylamino-acetylacetone and cyanoacetamide in the presence of an organic solvent and a basic catalyst selected from the group consisting of an aliphatic amine and a heterocyclic amine.

wherein R is an acyl group.

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